17 April 2009
KNOX GETS VICTORIA'S BIGGEST WETLAND
Melbourne Water has started work in the City of Knox on what is believed to be Victoria's largest constructed wetland.
The wetland will significantly improve the health of local waterways and create habitat for thousands of birds, fish and other animals.
Wetlands are shallow, vegetated pools that naturally filter out pollutants from stormwater runoff before it is released back into the environment. They also protect against flash flooding by holding water back so the stormwater system is not overwhelmed.
General Manager of Waterways, Chris Chesterfield, said that at 48 hectares, Dandenong Creek Wetlands is believed to be the biggest constructed wetland in Victoria and one of the biggest in the southern hemisphere.
"As the caretaker of waterways, one of the biggest challenges Melbourne Water faces is how to cut down the pollution washed into rivers, creeks and, ultimately, the bay," said Mr Chesterfield.
"Stormwater runoff from developed areas can carry a wide range of pollutants, ranging from nitrogen that causes algal blooms, to motor oil and animal droppings that affect the health of fish and platypus.
"Wetlands act as natural filters that soak up and break down pollution in stormwater before it gets into local rivers and creeks."
Mr Chesterfield said Melbourne Water had set a target of removing 100 tonnes of nitrogen from the waterways system by 2010 to improve the health of Port Philip Bay, making Dandenong Wetlands a major part of reaching this goal.
"We want Melbourne to become a watersmart city, and a big part of that is working out how to effectively manage stormwater pollution," he added.
"Our modelling shows that the Dandenong Creek Wetland will trap about 5,000 tonnes of suspended solids, 9 tonnes of phosphorus and 28 tonnes of nitrogen, helping to protect our waterways and the bay."
Around 1.6 million trees and shrubs will be planted to help form the wetlands, on what was formerly vacant Crown land and paddocks in Scoresby.
Melbourne Water has constructed more than 80 wetlands over the last ten years aspart of a $60 million program to improve the heath of waterways, including the Yarra.
Wetlands are becoming a common part of the urban landscape and provide increasing opportunities for stormwater reuse, which is expected to be an important part of a sustainable water future.
Melbourne Water acknowledges the assistance of Knox and Monash City Councils on finalising the project, as well as the Department of Sustainability and Environment, and Parks Victoria.
The Waterways Alliance – a partnership between Melbourne Water, Ecodynamics, Fulton Hogan and SMEC – will deliver the wetland projects on behalf of Melbourne Water. The project is expected to be completed in mid-2010.
Dandenong Creek Wetland – Key Stats
| Area of Wetland | 48 hectares |
| Construction cost | $15 million |
| Soil moved to create wetland | 315,000 cubic metres |
| Number of workers on site during construction | 40 (approx) |
| Wetland due to be completed | mid-2010 |
| Number of trees and shrubs | 1.6 million |
| Estimated pollution prevented from flowing into Dandenong Creek and Port Phillip Bay |
28 tonnes nitrogen 9 tonnes phosphorous 5,000 tonnes suspended solids |
Media Contact: Nicolas McGay (03) 9235 2278; 0438 981 836